Maggiolini Eugenio, Polimeno Laura, Todisco Francesco, Di Renzo Anna, Han Bo, De Giorgi Milena, Ardizzone Vincenzo, Schneider Christian, Mastria Rosanna, Cannavale Alessandro, Pugliese Marco, De Marco Luisa, Rizzo Aurora, Maiorano Vincenzo, Gigli Giuseppe, Gerace Dario, Sanvitto Daniele, Ballarini Dario
CNR NANOTEC, Institute of Nanotechnology, Lecce, Italy.
Dipartimento di Fisica, Università di Pavia, Pavia, Italy.
Nat Mater. 2023 Aug;22(8):964-969. doi: 10.1038/s41563-023-01562-9. Epub 2023 May 22.
Exciton-polaritons derived from the strong light-matter interaction of an optical bound state in the continuum with an excitonic resonance can inherit an ultralong radiative lifetime and significant nonlinearities, but their realization in two-dimensional semiconductors remains challenging at room temperature. Here we show strong light-matter interaction enhancement and large exciton-polariton nonlinearities at room temperature by coupling monolayer tungsten disulfide excitons to a topologically protected bound state in the continuum moulded by a one-dimensional photonic crystal, and optimizing for the electric-field strength at the monolayer position through Bloch surface wave confinement. By a structured optimization approach, the coupling with the active material is maximized here in a fully open architecture, allowing to achieve a 100 meV photonic bandgap with the bound state in the continuum in a local energy minimum and a Rabi splitting of 70 meV, which results in very high cooperativity. Our architecture paves the way to a class of polariton devices based on topologically protected and highly interacting bound states in the continuum.
源自连续统中光学束缚态与激子共振的强光-物质相互作用所产生的激子极化激元，能够继承超长的辐射寿命和显著的非线性特性，但在室温下于二维半导体中实现它们仍具有挑战性。在此，我们通过将单层二硫化钨激子与由一维光子晶体塑造的连续统中拓扑保护的束缚态相耦合，并通过布洛赫表面波限制来优化单层位置处的电场强度，从而在室温下实现了强光-物质相互作用增强以及大的激子极化激元非线性。通过一种结构化优化方法，在完全开放的架构中，此处与活性材料的耦合得以最大化，从而能够在局部能量最小值处实现具有连续统中束缚态的100毫电子伏特光子带隙以及70毫电子伏特的拉比分裂，这导致了非常高的协同性。我们的架构为基于连续统中拓扑保护且高度相互作用的束缚态的一类极化激元器件铺平了道路。
